What is the minimum plywood thickness required if floor joists are spaced 16 in O.C. according to FHA requirements?

The minimum plywood thickness required for floor sheathing when floor joists are spaced 16 inches on center is indeed 1/2 inch according to FHA requirements. This specification is based on ensuring sufficient structural integrity and load-bearing capacity for typical residential flooring applications. Plywood of this thickness provides a balance between strength and weight, ensuring that the floor can adequately support live and dead loads without excessive deflection or risk of failure.

Thinner plywood, such as 3/8 inch, may not provide the necessary strength for the given spacing of the joists, potentially leading to structural issues. Plywood thicker than 1/2 inch, such as 5/8 inch or 3/4 inch, while stronger, is often not required for this specific application, as the additional thickness may be more than what is necessary for standard residential flooring with joists at this spacing. This makes 1/2 inch the optimal choice for compliance with FHA guidelines while ensuring adequate performance.